(1) Field of the Invention
This invention is directed to an improved slide latch gravity lock for an article which includes novel means that prevent the lock from opening when the article is in its vertical position.
(2) Description of the Prior Art
Various prior art gravity lock mechanisms include the device described in U.S. Pat. No. 4,652,029, "Locking Mechanism for a Case." This patent discloses a carrying case lid having a hook thereon which is located within a container opening in the carrying case body when the carrying case is closed. A ball and an inclined surface on which the ball is free to roll is located within the container.
When the carrying case is closed and in a horizontal position, the ball does not prevent the hook (and the attached carrying case lid) from being moved away from the compartment in the carrying case body. However, when the carrying case is closed and in a vertical position, the ball is wedged between the hook and the compartment, and the hook (and the carrying case lid) is prevented from moving away from the compartment in the carrying case body. Unlike the present invention, the '029 patent does not utilize a sliding latch mechanism and, also unlike the present invention, the locking mechanism of the '029 patent is released automatically when the case is placed in a horizontal position.
Another prior art gravity lock is disclosed in U.S. Pat. No 3,756,639, "Orientation Sensitive Luggage Latch." The purpose of this gravity lock, unlike the purpose of the gravity lock of the present invention is to prevent the luggage from opening when it is in its horizontal, but wrongside-up position. The mechanism of this patent is also significantly different from that disclosed herein. Still another prior art gravity lock is disclosed in U.S. Pat. No. 3,828,899, "Orientation Sensitive Latch," wherein a gravity operated detent mechanism prevents luggage from being opened when in its wrongside-up position.
Other prior art gravity locks are shown in U.S. Pat. No. 530,862, "Lock," wherein a gravity lock prevents the case from being opened when the case is in its horizontal position and U.S. Pat. No. 4,346,924, "Releasable Fastening Device," wherein a briefcase is prevented from being opened when it is in its inverted position.